1 /*
2  * Copyright (C) 2009 SUSE Linux Products GmbH. All rights reserved.
3  *
4  * Authors:
5  *     Alexander Graf <agraf@suse.de>
6  *     Kevin Wolf <mail@kevin-wolf.de>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License, version 2, as
10  * published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
20  */
21 
22 #include <linux/kvm_host.h>
23 
24 #include <asm/kvm_ppc.h>
25 #include <asm/kvm_book3s.h>
26 #include <asm/book3s/64/mmu-hash.h>
27 #include <asm/machdep.h>
28 #include <asm/mmu_context.h>
29 #include <asm/hw_irq.h>
30 #include "trace_pr.h"
31 #include "book3s.h"
32 
33 #define PTE_SIZE 12
34 
35 void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
36 {
37 	mmu_hash_ops.hpte_invalidate(pte->slot, pte->host_vpn,
38 				     pte->pagesize, pte->pagesize,
39 				     MMU_SEGSIZE_256M, false);
40 }
41 
42 /* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
43  * a hash, so we don't waste cycles on looping */
44 static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
45 {
46 	return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
47 		     ((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
48 		     ((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
49 		     ((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
50 		     ((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
51 		     ((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
52 		     ((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
53 		     ((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
54 }
55 
56 
57 static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
58 {
59 	struct kvmppc_sid_map *map;
60 	u16 sid_map_mask;
61 
62 	if (kvmppc_get_msr(vcpu) & MSR_PR)
63 		gvsid |= VSID_PR;
64 
65 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
66 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
67 	if (map->valid && (map->guest_vsid == gvsid)) {
68 		trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
69 		return map;
70 	}
71 
72 	map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
73 	if (map->valid && (map->guest_vsid == gvsid)) {
74 		trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
75 		return map;
76 	}
77 
78 	trace_kvm_book3s_slb_fail(sid_map_mask, gvsid);
79 	return NULL;
80 }
81 
82 int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
83 			bool iswrite)
84 {
85 	unsigned long vpn;
86 	kvm_pfn_t hpaddr;
87 	ulong hash, hpteg;
88 	u64 vsid;
89 	int ret;
90 	int rflags = 0x192;
91 	int vflags = 0;
92 	int attempt = 0;
93 	struct kvmppc_sid_map *map;
94 	int r = 0;
95 	int hpsize = MMU_PAGE_4K;
96 	bool writable;
97 	unsigned long mmu_seq;
98 	struct kvm *kvm = vcpu->kvm;
99 	struct hpte_cache *cpte;
100 	unsigned long gfn = orig_pte->raddr >> PAGE_SHIFT;
101 	unsigned long pfn;
102 
103 	/* used to check for invalidations in progress */
104 	mmu_seq = kvm->mmu_notifier_seq;
105 	smp_rmb();
106 
107 	/* Get host physical address for gpa */
108 	pfn = kvmppc_gpa_to_pfn(vcpu, orig_pte->raddr, iswrite, &writable);
109 	if (is_error_noslot_pfn(pfn)) {
110 		printk(KERN_INFO "Couldn't get guest page for gpa %lx!\n",
111 		       orig_pte->raddr);
112 		r = -EINVAL;
113 		goto out;
114 	}
115 	hpaddr = pfn << PAGE_SHIFT;
116 
117 	/* and write the mapping ea -> hpa into the pt */
118 	vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
119 	map = find_sid_vsid(vcpu, vsid);
120 	if (!map) {
121 		ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
122 		WARN_ON(ret < 0);
123 		map = find_sid_vsid(vcpu, vsid);
124 	}
125 	if (!map) {
126 		printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
127 				vsid, orig_pte->eaddr);
128 		WARN_ON(true);
129 		r = -EINVAL;
130 		goto out;
131 	}
132 
133 	vpn = hpt_vpn(orig_pte->eaddr, map->host_vsid, MMU_SEGSIZE_256M);
134 
135 	kvm_set_pfn_accessed(pfn);
136 	if (!orig_pte->may_write || !writable)
137 		rflags |= PP_RXRX;
138 	else {
139 		mark_page_dirty(vcpu->kvm, gfn);
140 		kvm_set_pfn_dirty(pfn);
141 	}
142 
143 	if (!orig_pte->may_execute)
144 		rflags |= HPTE_R_N;
145 	else
146 		kvmppc_mmu_flush_icache(pfn);
147 
148 	/*
149 	 * Use 64K pages if possible; otherwise, on 64K page kernels,
150 	 * we need to transfer 4 more bits from guest real to host real addr.
151 	 */
152 	if (vsid & VSID_64K)
153 		hpsize = MMU_PAGE_64K;
154 	else
155 		hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
156 
157 	hash = hpt_hash(vpn, mmu_psize_defs[hpsize].shift, MMU_SEGSIZE_256M);
158 
159 	cpte = kvmppc_mmu_hpte_cache_next(vcpu);
160 
161 	spin_lock(&kvm->mmu_lock);
162 	if (!cpte || mmu_notifier_retry(kvm, mmu_seq)) {
163 		r = -EAGAIN;
164 		goto out_unlock;
165 	}
166 
167 map_again:
168 	hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
169 
170 	/* In case we tried normal mapping already, let's nuke old entries */
171 	if (attempt > 1)
172 		if (mmu_hash_ops.hpte_remove(hpteg) < 0) {
173 			r = -1;
174 			goto out_unlock;
175 		}
176 
177 	ret = mmu_hash_ops.hpte_insert(hpteg, vpn, hpaddr, rflags, vflags,
178 				       hpsize, hpsize, MMU_SEGSIZE_256M);
179 
180 	if (ret < 0) {
181 		/* If we couldn't map a primary PTE, try a secondary */
182 		hash = ~hash;
183 		vflags ^= HPTE_V_SECONDARY;
184 		attempt++;
185 		goto map_again;
186 	} else {
187 		trace_kvm_book3s_64_mmu_map(rflags, hpteg,
188 					    vpn, hpaddr, orig_pte);
189 
190 		/*
191 		 * The mmu_hash_ops code may give us a secondary entry even
192 		 * though we asked for a primary. Fix up.
193 		 */
194 		if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
195 			hash = ~hash;
196 			hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
197 		}
198 
199 		cpte->slot = hpteg + (ret & 7);
200 		cpte->host_vpn = vpn;
201 		cpte->pte = *orig_pte;
202 		cpte->pfn = pfn;
203 		cpte->pagesize = hpsize;
204 
205 		kvmppc_mmu_hpte_cache_map(vcpu, cpte);
206 		cpte = NULL;
207 	}
208 
209 out_unlock:
210 	spin_unlock(&kvm->mmu_lock);
211 	kvm_release_pfn_clean(pfn);
212 	if (cpte)
213 		kvmppc_mmu_hpte_cache_free(cpte);
214 
215 out:
216 	return r;
217 }
218 
219 void kvmppc_mmu_unmap_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
220 {
221 	u64 mask = 0xfffffffffULL;
222 	u64 vsid;
223 
224 	vcpu->arch.mmu.esid_to_vsid(vcpu, pte->eaddr >> SID_SHIFT, &vsid);
225 	if (vsid & VSID_64K)
226 		mask = 0xffffffff0ULL;
227 	kvmppc_mmu_pte_vflush(vcpu, pte->vpage, mask);
228 }
229 
230 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
231 {
232 	struct kvmppc_sid_map *map;
233 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
234 	u16 sid_map_mask;
235 	static int backwards_map = 0;
236 
237 	if (kvmppc_get_msr(vcpu) & MSR_PR)
238 		gvsid |= VSID_PR;
239 
240 	/* We might get collisions that trap in preceding order, so let's
241 	   map them differently */
242 
243 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
244 	if (backwards_map)
245 		sid_map_mask = SID_MAP_MASK - sid_map_mask;
246 
247 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
248 
249 	/* Make sure we're taking the other map next time */
250 	backwards_map = !backwards_map;
251 
252 	/* Uh-oh ... out of mappings. Let's flush! */
253 	if (vcpu_book3s->proto_vsid_next == vcpu_book3s->proto_vsid_max) {
254 		vcpu_book3s->proto_vsid_next = vcpu_book3s->proto_vsid_first;
255 		memset(vcpu_book3s->sid_map, 0,
256 		       sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
257 		kvmppc_mmu_pte_flush(vcpu, 0, 0);
258 		kvmppc_mmu_flush_segments(vcpu);
259 	}
260 	map->host_vsid = vsid_scramble(vcpu_book3s->proto_vsid_next++, 256M);
261 
262 	map->guest_vsid = gvsid;
263 	map->valid = true;
264 
265 	trace_kvm_book3s_slb_map(sid_map_mask, gvsid, map->host_vsid);
266 
267 	return map;
268 }
269 
270 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
271 {
272 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
273 	int i;
274 	int max_slb_size = 64;
275 	int found_inval = -1;
276 	int r;
277 
278 	/* Are we overwriting? */
279 	for (i = 0; i < svcpu->slb_max; i++) {
280 		if (!(svcpu->slb[i].esid & SLB_ESID_V))
281 			found_inval = i;
282 		else if ((svcpu->slb[i].esid & ESID_MASK) == esid) {
283 			r = i;
284 			goto out;
285 		}
286 	}
287 
288 	/* Found a spare entry that was invalidated before */
289 	if (found_inval >= 0) {
290 		r = found_inval;
291 		goto out;
292 	}
293 
294 	/* No spare invalid entry, so create one */
295 
296 	if (mmu_slb_size < 64)
297 		max_slb_size = mmu_slb_size;
298 
299 	/* Overflowing -> purge */
300 	if ((svcpu->slb_max) == max_slb_size)
301 		kvmppc_mmu_flush_segments(vcpu);
302 
303 	r = svcpu->slb_max;
304 	svcpu->slb_max++;
305 
306 out:
307 	svcpu_put(svcpu);
308 	return r;
309 }
310 
311 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
312 {
313 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
314 	u64 esid = eaddr >> SID_SHIFT;
315 	u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
316 	u64 slb_vsid = SLB_VSID_USER;
317 	u64 gvsid;
318 	int slb_index;
319 	struct kvmppc_sid_map *map;
320 	int r = 0;
321 
322 	slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
323 
324 	if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
325 		/* Invalidate an entry */
326 		svcpu->slb[slb_index].esid = 0;
327 		r = -ENOENT;
328 		goto out;
329 	}
330 
331 	map = find_sid_vsid(vcpu, gvsid);
332 	if (!map)
333 		map = create_sid_map(vcpu, gvsid);
334 
335 	map->guest_esid = esid;
336 
337 	slb_vsid |= (map->host_vsid << 12);
338 	slb_vsid &= ~SLB_VSID_KP;
339 	slb_esid |= slb_index;
340 
341 #ifdef CONFIG_PPC_64K_PAGES
342 	/* Set host segment base page size to 64K if possible */
343 	if (gvsid & VSID_64K)
344 		slb_vsid |= mmu_psize_defs[MMU_PAGE_64K].sllp;
345 #endif
346 
347 	svcpu->slb[slb_index].esid = slb_esid;
348 	svcpu->slb[slb_index].vsid = slb_vsid;
349 
350 	trace_kvm_book3s_slbmte(slb_vsid, slb_esid);
351 
352 out:
353 	svcpu_put(svcpu);
354 	return r;
355 }
356 
357 void kvmppc_mmu_flush_segment(struct kvm_vcpu *vcpu, ulong ea, ulong seg_size)
358 {
359 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
360 	ulong seg_mask = -seg_size;
361 	int i;
362 
363 	for (i = 0; i < svcpu->slb_max; i++) {
364 		if ((svcpu->slb[i].esid & SLB_ESID_V) &&
365 		    (svcpu->slb[i].esid & seg_mask) == ea) {
366 			/* Invalidate this entry */
367 			svcpu->slb[i].esid = 0;
368 		}
369 	}
370 
371 	svcpu_put(svcpu);
372 }
373 
374 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
375 {
376 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
377 	svcpu->slb_max = 0;
378 	svcpu->slb[0].esid = 0;
379 	svcpu_put(svcpu);
380 }
381 
382 void kvmppc_mmu_destroy_pr(struct kvm_vcpu *vcpu)
383 {
384 	kvmppc_mmu_hpte_destroy(vcpu);
385 	__destroy_context(to_book3s(vcpu)->context_id[0]);
386 }
387 
388 int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
389 {
390 	struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
391 	int err;
392 
393 	err = __init_new_context();
394 	if (err < 0)
395 		return -1;
396 	vcpu3s->context_id[0] = err;
397 
398 	vcpu3s->proto_vsid_max = ((u64)(vcpu3s->context_id[0] + 1)
399 				  << ESID_BITS) - 1;
400 	vcpu3s->proto_vsid_first = (u64)vcpu3s->context_id[0] << ESID_BITS;
401 	vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
402 
403 	kvmppc_mmu_hpte_init(vcpu);
404 
405 	return 0;
406 }
407